Chart 15.2. – Major endocrine and nonendocrine causes of secondary HT, signs, and diagnostic screening.
| Clinical findings | Diagnostic suspicion | Additional findings |
|---|---|---|
| Nonendocrine causes | ||
| Edema, anemia, anorexia, fatigue, high creatinine and urea, and changes in urinalysis or imaging examinations | Renal parenchymal disease | Creatinine and eGFR calculation (I: B), renal US, urinalysis (I: C) for dysmorphic proteinuria/hematuria. Albuminuria or proteinuria/urine creatinine ratio where indicated (LR: I; LE: B) |
| Sudden-onset HT or apparently unexplained worsening before age 30 or after 55, resistant or refractory HT or MHT, abdominal murmur, sudden APE, unexplained alteration in renal function or caused by RAAS blockers, kidney asymmetry > 1.5 cm | Renal artery stenosis | Renal Doppler US with flow velocity measurement and resistivity index (screening, but observer-dependent) (LR: I; LE: B) and/or captopril radioisotope renography (LR: III; LE: C), MNR angiography (eGFR > 30 mL/min, BOLD or digital subtraction) (LR; I; LE: B) or spiral CT (eGFR > 60 mL/min (LR: I; LE: B) Gold standard: conventional renal arteriography (LR: I, LE: A) |
| Higher frequency in men or postmenopausal women, snoring on most nights, sleep fragmentation with respiratory pauses or choking, excessive daytime sleepiness, nonrestorative sleep, fatigue, nocturia, morning headaches, MS | Obstructive sleep apnea (OSA) | Surveys have low accuracy for screening purposes Gold standard: polysomnography or home respiratory polygraphy. AHI < 5 events/h: no OSA; AHI 5-14.9 events/h: mild OSA; AHI 15-29.9 events/h: moderate OSA; AHI ≥ 30 events/h: severe OSA |
| Weakness in LLs, absent pulse or diminished amplitude, HT with SBP 10mm Hg > in ULs over ULs, interscapular and thoracic systolic murmur | Coarctation of the aorta | Chest X-ray, screening echocardiogram CT angiography of the chest or, preferably, aortic MNR (gold standard) Invasive angiography, only when additional data are required |
| Endocrine causes | ||
| RHT or RfHT and/or with hypopotassemia (non obligatory) and/or with adrenal nodule | Primary hyperaldosteronism (hyperplasia or adenoma) | Aldosterone measurements (>15 ng/dL) and plasma renin activity/concentration; aldosterone/renin ratio > 30 Confirmatory testing (see Chart 15.7 ) Imaging examinations: thin-slice CT or MNR. Selective aldosterone and cortisol adrenal sampling to identify subtype, when indicated (LR: I; LE: B) |
| Paroxysmal HT with triad consisting of headaches, sweating, and palpitations | Pheochromocytoma and paragangliomas | Free plasma metanephrines and/or urinary fractionated metanephrines (LR: I, LE: A). CT (LR: IIa, LE: B) (screening), MNR (LR: I; LE: B) and scintigraphy (LR: IIa, LE: C) where indicated |
| Fatigue, weight gain, hair loss, diastolic HT, muscle weakness, sleepiness | Hypothyroidism | Screening: TSH and free T4 (LR: I, LE: B) |
| Increased sensitivity to heat, weight loss, tachycardia/palpitations, exophthalmos, hyperthermia, hyperreflexia, tremors, goiter | Hyperthyroidism | Screening: TSH and free T4 (LR: I; LE: B) |
| Renal lithiasis, osteoporosis, depression, lethargy, muscle weakness or spasms, thirst, polyuria, polydipsia, constipation | Hyperparathyroidism (hyperplasia or adenoma) | Total and/or ionized calcium, phosphorus, PTH, 24-hour urine calcium and vitamin D level (LR: I; LE: B) |
| Weight gain, decreased libido, fatigue, hirsutism, amenorrhea, moon face, “buffalo hump”, purple striae, central obesity, hypopotassemia | Cushing’s syndrome (hyperplasia, adenoma and excess secretion of ACTH) | Baseline cortisol, midnight salivary cortisol, 24-h urinary free cortisol, and betamethasone or dexamethasone suppression test (take 1 mg dexamethasone between 11 PM and midnight and measure serum cortisol level at 7-8 AM of the following morning). CT, MNR (LR: I; LE: B) |
| Increased visceral or central fat | Obesity Class 1: BMI 30 to < 35 kg/m 2 Class 2: BMI 35 to < 40 kg/m 2 Class 3: BMI ≥ 40 kg/m 2 | BMI (weight in kg/height in m 2 ) and abdominal circumference (> 102 cm in men and 88 cm in women) Imaging examinations: DEXA (gold standard), CT, MNR (clinical trials) (LR; I; LE: B) |
| HT in up to 30% of cases, in addition to diabetes, LVH, and OSA. Other symptoms: visual defects, cranial nerve palsy, headaches, macrognathism, growth of feet and hands, soft tissue hypertrophy, macroglossia, musculoskeletal complications | Acromegaly | IGF-1 (I, B) measurement, GH serum level and GH after oral glucose overload (I, B) Location: sella turcica MNR (preferred) or CT scan |
ACTH: adrenocorticotropic hormone; AHI: apnea–hypopnea index; APE: acute pulmonary edema; BMI: body mass index; BOLD: blood oxygen level-dependent; CT: computed tomography; DEXA: dual-energy x-ray absorptiometry scanning; eGFR: estimated glomerular filtration rate; GH: growth hormone; IGF-1: insulin-like growth factor 1; LVH: left ventricular hypertrophy; MHT: malignant hypertension; MNR: magnetic nuclear resonance; OSA: obstructive sleep apnea; PTH: parathormone; RAAS: renin-angiotensin-aldosterone system; RHT: resistant hypertension; TSH: thyroid-stimulating hormone. LLs: lower limbs; ULs: upper limbs.